Selective signaling system.



J. ERIOKSON.

SELEGTIVE SIGNALING SYSTEM.

APPLICATION FILED AUG.16, 1905.

Patented Feb. 14, 1911.

15 with the some Unrrnn STATES PATENT OFFICE.

JOHN ERIGKSON, OF (EHIUAGU, ILLINOIS, ASSIGNOR, BY MESNE ASSIGNMENTS, To FIRST TRUST AND SAVINGS BANK, TRUSTEE, F GHIOAGG, ILLINOIS.

SELECTIVE SIGNALING- SYSTEM.

oeiceoe,

Specification of Letters Patent.

Pateiiteo. Feb. 14., 1911.

Application filed August 16, 1905. Serial No. 274 ,91h

resident of Chicago, (look county; Illinois, have invented a certainnewund userul imjirovement in th-zlcetire Signaling Systems, of which the following; is s spemficction. Muinvcn on relute ing; L stems in genernh but more partied- 0 selective ti ggnuling systems of such character that any one of a plurality of Sig rialo'ec ring dm ioes can be operated to the exclusion o t? others, even though the s'aid signaldeceiving d s are all connected and especially to seb y .s :vhich are i.dapted more particularly for ..;e in connection with e perty line telephone system. Generally stated the object of my inven- '20 tion is the prorision of an improved and highly etlioieht selectivesignaling system.

Special. objects of my invention are the provision of on improved construction and arrangement whereby dii'lerent electric one rents may be employed for selectively ringing 4, number of bells which are distributed "along at party telephone line, it being possible i or the operator at the exchange or central stati on to ring any bell to the exclusion 3,0 of the others by simply pressing one-of a corresponding number of ringing; keys on the switchboard; the provision of an im- 1 proved construction and arrangement Whereby the different bells or ringers located at the different stations along a. party telephone line may be selectively. rung" or operated by means of a pair of alternating current generators which are bridged in series across the operator-s cud-circuit, the middle point. of the bridge between the generators being grounded with respect to ground connections provided at the subscribers stations, and the operator being; provided with switching apparatus of such character that current from the first generator may be thrown upon' one side of the telephone line, .that current from the second generator may be thrown upon the other side of the line that current from the said second generator may be thrown upon both sides of the line,

or so that current from thefirst generator may be thrown on' one side of the line at the some time that current f'rmn the second generator thrown upon the other side of the li-nc,.. thus giving the four diiieren't electri to electrical signal col. conditions in the mrtylinc, and thus enabling the operator to signal any sub somber Without ringing the bells at the other stations on the M. 1e line, it being under magnetic locking arrangement for the scribers bells or ringers of such character that when the operator presses the proper key for ringing one hell, the strikers of all other bells on the same line will be prevented from vibrating, thus pern'iitting the operzitor to operate any bell or ringer will; the provision of on improved construction and circuit arrangement for the polarized electric bells or ringers comprised in the sig nal-receiving apparatus of the selective signaling system of :1 party-line telephone system; and the provision of certain details of construction and features of improvement, tending to increase the general efliciencyand desirability of a party-line telephone system of'this particular character.

To the foregoing and other i fol endsmy invention consists in matters hereinafter set forth and claimed.

In the accompanying drawings, Figure- 1 is a diagra-m illustrating the construction and circuit arrangement of a party-line telephone system embodying the principles of my invention. Fig. 2 is a diograimnatic View illustrating another form of electric hell or ringer for the subscribers signalreceiying apparatus. 7

As thus illustrated, the jack 2 represents one of the line-terminals at the central eta-- tion, but it Will be understood that the style of such terminals is unimportant. The con ductors 3 and 4 of one of the pguiy lines, in connection with which I have elected to de-- scribe my invention, terminate in the said jack 2; and the four subscriber. stations A; B, C eno'LD are-bridged across said line in the order named, through the medium of the condensers 5 and 6, 7 and 8, 9 and 10. and 11 and 12, respectively. Station A, .for example, is provided with two condensers 5 and 6, to which-are connected the leads that pass through the ringer 13; Said ringer is of the usual type, having a core provided with twowindings 14 and 15, each coil being of approximately 500 ohms.- The armature 3.;6 is of course; polerized and of the jack 2'and the pivoted to any suitable support by means of I pressed for a reasonable length of time, the

a pin 17, which latter passes through the direction of the current will then be recentral portion of the tends at right angles to'the pole-pieces 13 and 19. Said armature carries areed 20 to the end of which is secured a ball 21. Said ball, when the pole-picce 18 attracts the armature 16,'strikes the bell 22. To the said ball, on the side away from the bell, there is attached a shoe 23, of magnetic material, which is secured to said ball loosely by the screw 24. Normally, the armature 16 is at rest in such manner that the shoe 23 is in contact with the pole-pieces 25 and 26 of the controlling magnet. 27. Said magnet comprises a core upon which the coils 28- and' 29 are Wound. If said core. becomes magnetized, the shoe-like armature 23,- being attracted, prevents the ball 21 from vibrating back and forth and from striking the bell 22. The generators E and F are connected in series, and care is taken that they run in synchronism. The common connecing conductor 30 is connected to ground at In Fig.1, the cord conductors 31 and 32 are shown-temporarily connected with the line-conductors 4 and 3 through the medium scription, and solely for the sake of clear ness, the conductor .3 will be known as the sleeve-conductor, and the conductor 4 as the tip-conductor. For the same reason, it will be assumed that the armatures of the gen- .positions that the terminals 34 .and 35 may be considered negative terminals, and the eratorsE and F are, for an instant, in such terminals 36 and 37 positive. Then the connections being as indicated, and when the push-button 38 is pressed, a flow of current passes from the generator E along the eonand the windings 14 'i dirctor 39 and through the springs 40 and 41 to the conductor-32, thence to the line conductor 3, through each of the condensers t G G and ,G, back .5, 7, 9 iand'11 to the ground-terminals G to the grounded terminal G, and then to the generator E. Of 13, 42, 43 and 44, bridged party-line in question, only the one at the station A will become active, and The path of the conductor 3, through uie condenser 5 andllji of the ringer 13 to the'g'round terminal G and back to the generator E. The windings onthe ringer 13 are so arranged that they reinforce or augment each other. -There ..being no other forces to}. befconsidered-"at' the time, the armature' 16 being. polarized positively (as are the other ringer armatures) is attracted ..t'o the pole-piece 18 and repelled from the Strike the bell 22' and polc p ece 19. Therefore, the. ball 21 will prodiice a signal. It

.is very evident that if the button 38 is armature and ex-[ erators are altcrnators, and that in time,

plug 33. In this de .versed through the ringer 13, since the gencausing the bell to ring. This form of ringer is, however, very common. At station B the current, in passing from conductor 3 to the ground terminal. Cl", passes only through the windings 44 and 43 0'1' the magnet 45. These coils are so Wound that the clectromagnet 45 becomes onergized, and the shoe 46 attracted and held to the pole-pieces 47- and 48. I It is evident that as long as any'ourrcnt passes through the electromagnet in ques-' tion, in any direction, the armature or shoe 46 Will be held, and that the ringer at the second station will remain silent-,because the ball 49 has no tendency to be moved by the armature 50; At the third station C the current passes through the conductor 9, the

coil 51 of the ringer 43, and the coil 52 of the electromagnet 53, to the ground terminal G elect-romagnet- 53 become energized, since the current passes throughone of the wind ings in each. The shoe 54 of the ball 55 will be attracted by the pole-pieces 56 and 57; therefore, said the ringer 59 and prevented from giving a signa The magnetic force of the electro-.

magnet 53 is stronger than that developed at the ringer 43, owing to the air-gap between the armature 5S and the pole-piece 6%, so that the ringer apparatus at this sta tien C remains silent. At the fourth station I) the currentfrom the conductor 3 passes through the condenser 11 and the coils 61 'and- ($2 to the ground terminal G The pole pieces 63 and 64 are thus magnetized, andthe clectromagnet 65.1's magnetized also. Thc.armatnre 66 is then attracted by the pole-piece 63 and repelled by the pole-piece 64. be to force the ball (37 against the bell 68; but the magi'letic force at the el'ectromagnet (l5, owing to the closed magnetic circuit through the shoe (39, is strong enough to OVQI'COIHG the force 'cleveloped by the ringer 44. The latter force is weaker by reason of the air-gap between the armature 66 and the pole-piece 63. Eventually, the current is reversed, and the 63 and 64 will be reversed likewise, but still the armature {59 will beheld by the pole pieces 7 0 and 71. Thus it is clear that when the button 38 is pressed, onlyone station the station A+will respond and give a sig The tendency, therefore, will polarity of the pole-pieces i In this case both the ringer 43 and'the ball will be held away from 5 come energized.

d troniagnet and the ringm become 2'0 springs 71 and 72 and t 25 through the ground term 1), 27; and through the -'o from the ground terminal G Slugainst the pole-piecee and 2 '3 and there being no me nal. In this way, the signaling uppurutus at the first station becomes uclii'c c: we he ringer 13 become cnergizml. and mouse the controlling clectromugnot 5-2 doc, not be At the second station the bell is kept silent hecuuse the controlling magnet :45 becomes ruug nctizcd while the ringer-magnet reunion; deincij-gized. At the third station, both the controlling elecenergized root pr nts a closed the ringer-electrocircuit, the

but since theelcctrouu magnetic circuit, and magnet 1111- open niuguetic former overcomes the tendency oi. the latter to produce any vibration oi the ring -urnouture; and at the fourth stutiou the same thing is true. l'Vl'ien the pusl'i-lnitton 70 is pressed, the tip-coiuluctor 4 1' through c ingliuin of the conch and the nduetor T3,

teri'oinul W1 5.]. then 'placed in connection Wu of, the generator .l A cur enflow from the terminal 3? of s F to the grounded tEI'lHliFl G. and thence {Li- G, G i and G of the several stations to the tip-conductor l. 'At the first station the current passes from. the ground teru'unal {i= tlnough lthewindings :28 and 29 the elect-romegnet condense-1'" 6 to the tip conductor i. Since the windings of said .electromagnet reinforce or aug; umt each other, the letter becomes n'iegnetized, and the shoe 23 and the ball are held securely There being no energizing current through the ringer-magnet 13, there will. he no tendency at that station to ring "he hell the second station E, hovs the rent irough. the windings 7% and iii, and through the con denser 8, to the tip-concluctcr 4.. These windings. reinforcing or augmenting each other, the ringer-magnet becomes energized, gnctizing force at the controlling magnet 45, the bell 76 is rung. At the third'stution the current passes from the ground terminal G through the coil 77 of the-magnet 53, and. through the coil 78 of the ringer 43, thence thri'uigh the condenser 10 to the tip-conductor Both the controlling magnet 53 and the ringer-magnet- 43 become energized, but the force of the former overcomes that in the letter, because the. .a.irga.p between the armature 58 and the pole-piece 60, which renders the reluctance of the magnetic circuit including said armature and pole-piece comparatively large, consequently, 'no signaling sound is produced at station tion-station D.-the current passes from the ground terminal Grj through the Winding 79 of the controlling magnet 535, through the coil 80 and through the condenser 12, to the tip-conductor 4. For the some reason generator (1- At the fourth staascribed to the third station, this station also remains silent. lmtton is pressed oul the second station Ill responds. Again, when the button 81 'uossed, the c-oiuluctors 3!. and 372 are brought together by the s 'n'ings 82, and and placed in conuectiol'i. with the lead 73 that constitutes the terminal 35 oft-the generator F. The current, therefore, tl'uxough the ground teri'uinuls G (1 G- und G", and branches in each station to the tip end conductors 4 and 3 to the generator'tcrmi nul Q At the first station the -urrout passes through the ground terminal G. the coils 15 and 14 of the ril'ig'crunugnet 18, through the condenser to the sleeve-com]uctor and also from the ground terminal (2. through the windings and 29 of the cow trolling nmgnct 27, and through the condenser (i to the tip-conductor (t. it is mi dent then that since both whirling; of the ringer-magnetand both windiu got the controlling magnet reinforce or uuguwut each other, both of said u'ulgnels become c1ierg'ized. The latter, lion-ever has the ad vantage over the former, in that its mug-- nctic circuit is strong enough to overcozm: the pull of the former, because of the air guy between the armature 16 piece 18. Therefore, the sounder 21 is retained away from the ringer At the second station the current passes from the ground terminal G through botlwthe "wind ings 74. andof the ringeruuugnct 42, and thence to the tipc onductor 4:. through the condenser S, and by another brunch through the windings 43 and 4 1- of the controlling magnet 45 to the SlE8VQ--C()Il(lllClOl' 3. through the coudenser 'i'. Both the ringer and the controlling magnets become encrgized, as in the first station, but for the same reasonset forth in councctirm with said first station, when the controlling imzgnet becomes magnetized the signaling uppuratus at the second station does not be- ,come operative. jAt,the third stu'tion the two current-branches extend from the ground terminal G through the inding 7701? the controlling magnet 53,,und the Winding.78 of the ringer-magnet 43 to the tip-conductor 4;, and from the ground ten minal G through the coils 52 and 51 to the sleeve-conductor 3. In this case, the way in which the. current passes through the coils 77 and 52 of thecontrolliug magnet renders said magnet neutral. However, the magnetic force developed in the coils of the ringer-magnet causes the said coils to reinforce or augment each other, and the result is that the armature 58 of that ringer-naugnet. 43 is operated by the ringing current. At the fourth" station the current at the ground terminal-.G divides and flows over two paths. 7 One path is through the coil 62 "lhcrct'ore, when the and the polc of the magnet 65, and through the coil 61 of ling magnct27, after which o 'zcratioi'i it will the ringer-magnet it to the sleeve-conductor 3; and the other circuit is through the coils 7t) and 80 to the tip-conductor 4-. The current passing through the coils-61 and 80 ot' the ringer-magnet 44- neutralizes their niagnctie properties, while the coils in the controlling iiiagnet' reinforce or augment each other, and iii this way retain the striker 67, through the shoe 69, against the pole-pieces 7t) and 71. Thus it is .ecn that when the third push-button 81 is depressed, only the j ringing apparatus at the third station beeach station, but no circuit will be closed through the ground. This'is true, since each of the four coils associated with the ringing apparatus at each station is of approximately 500 ohms resistance. The cur-' rent in passing from the sleeve-coniluctor 3 to the tip-conductor 4, through the first station, through the coils 14 and- 15, and through the coils 2S and 29, inagnetizes both 'the ringer-magnet and the controlling ,inagnet; but since the magnetic c-ircuitof the latter has a. lower reluctance than the magnetic circuit of the former, owing to the airgap between the armature 16 and the polepieee 18, the armature 1G is prevented from vibrating by the attraction of the shoe to the pole-pieces 25 and 26. At the second statlon both the magnets also become energized, and for the reason described in con nect-i on witl fhc first station, the ringer is prevented from opera-t1ng.. At the third station the windings 5 2 and 77 of the. colitrolling magnet. reinforce or augment cach' other, but those of the ringer-magnet 43 cancel or neutralize each other, and the ringers remain qulet. Atthe fourth station the windings of the controlling magnet neutralize each other, while those of the' ringer-magnet reinforce or augment each other, with the result'that. the armature 66 ribrates iniiniscii with thecurrent. When the button 85 pressed, and the line-conduetors 3 and 4 connected across the ringer generators E and F, in the mannerem,

plain'ed, i.t was-stated that the stations A, B and C would remain.inopeiative. Re-

Ierring to station A, 1tthe armature 16' happens tobe so situated that the .shoe '23 is not against the pole-pieces of the control ling magnet 27,-sa d armature will then more until the shoe 23 strikestlie control scribed in Fig. 1.

rei'i'iaiii locked, for reasons already de scribed. Tl10 same ii'iight be true of any other station' when some one ot the ringingbuttons 38, 7t), 81 or is pressel. This,

however, is of no ii'iiportance, and does not and by the use of the series of contact;

asdescribc-d, a combipoii'its substantially attained by which an;

nation of circuits one of four stations on a. line may be signalcd without disturbing'a ny one of the other stations on the same line. It. is also evident that by means of a plug, or any other suitable means, the circuits connecting with the generators of the central otiice may be temporarily joined to any oi. the partylines which may terminate in said central Four stations have been described station. on a line in Fig. 1, butit will be understood that it is not. essential for practical purposes that there be such i 11111i1lJEI't-liflt .is, any number can be employed. If desired, single station (the fourth or D station, for instance) could be'signaled, if it were the only one on the line, by depressing the proper button, in this case button 85. current will pass from the conductor 3 through the ringing apparatus, as previously described, and back to theother conductor 4 and for reasonsalready pointed out the hell .would be rung. The same is true of any other one or more of the stations already described.

ing apparatus of,my invention.

The-

case two bells 8S and 89 are supplied, iii-.J

stead of one, and the controlling magnet 90 is put to one side, with the reed v91 carrying the magnetic shoe 9?. 011 the ballDZi', and a' separate reed 94 carries the ringer-ball 95.

In using this modified ringing apparatusthere would be no change'in the coi'incction from what has'already been described. The

spring @98- and sleeve 99, and the tour .fst-a' tions bridged across said line'would be ar-' ranged inharinony with the stationsl de- 33 to the jack- 96, the operation of the instri'iinents on said"line would he identical with those previously described. Although I have illustrated certain apparatus and 011 If another By applying the plug and a calling apparatus normally discoir' ceiving means and each signal-receiving means comprising a polarized ringer, and a magnet adapted when energized to prevent the bell from 1'1l1g1l1g,tl16 operating circuit of at least one signal-receiving meansincluding the bell in series. with a winding of its associated magnet.

it selective signaling system comprising a metallic line-circuit, a pluality oi. signal-receiving meansbridged across the said line-circuit, eaclrbridge being grounded and including a pair of condensers arranged at opposite sides of the signal-rcceiving means,- and a, calling apparatus tor selectively operating the said signal-receiving means over the said line-circuit, said calling apparatus including a plurality of alternating current-gcnerators connected in series, and each connected-with ground, together with a plurality of selective ringingkeys corresponding in number to the signalreceiving means, and adapted for connecting up the generators in as many different circuits as there are signal-receiving means,

and each signal-receiving means comprising a polarized ringer, and a magnet adapted when energized to prevent the bell from ringing, the operating circuit of at least one signal-rcceiving means includingt-he bell in series with a winding of its associated magnet.

6. A selective signaling system comprising a complete metallic subscribcrs line, a spring-jack in which the said line terminates, a cord-circuit provided. with a plug adapted for insertion in said jack, a plurality of alternating current-generators connected in series and grounded at a. point between them, a plurality of keys for variously connecting the generators with either one or both sides of the cord-circuit, and a plurality of signal-receiving means lu-idgcd across the said line, each bridge being grounded, and each signal-receiving means being adapted to be operated by its allotted key and no other, and each signal-receiving means comprising a polarized ringer, and a magnet adapted when energized to prevent the bell from ringing, the operating circuit of at least one signal-receiving means including the bell in series with a winding of its associated magnet.

7. A selective signaling system con'iprising a complete metallic subscribers line, a

pluralit-yof signal-receiving means bridged across the said circuit, each bridge being grounded and including a pair of condensers arranged at opposite sides of said signalreceiving means, and a calling apparatus normally disconnected from the said line, but adapted to be connected thereto for the purpose of selectively operating the said signal-receiving means over the said line, said calling apparatus including a plurality of alternating cnrrent-generators, together with switching devices adapted for variously connecting oneior more of said generators with either one or both sides of the line-- circuit, and whereby said generators may be connected up in as many different circuits as there are signal-receiving means, each signal-receiving means being responsive only when its alloted circuit is closed, and each signal-receiving means comprising a polarized ringer, and a magnet adapted when energized to prevent the bell from ringing, the operating circuit of at least one signal-receiving means including the bell in series with a winding of its associated magnet.

8. Aselectivc signaling system comprising a line -circuit, four signaln'eceiving means connected with the said'circuit, and a calling apparatus for selectively operating 'said sigmd-receiving means over the said circuit, said calling apparatus including a couple of synchronized alternating currentgenerators, said generators being connected in series and'grouiided; at a point between them, and each signal-receiving means comprising a polarized electric bell, and an elcctro-niagnet bridged in serieswith the coils'of'the' bell and adapted when energized t5 prevent the latter from ringing:

9, A selective signaling system comprising a line-circuit. four signal-receiving means connected with the said circuit. and falling apparatus for sel ctively operating the said signal-receiving means'over the said. circuit, said calling apparatus including-a couple of generators connected in series and grounded at a point between them, and each signalreceiving means comprising a polarized electric bell, and an electro-magnet bridged in series with the coils of the bell and adapted when energized to prevent the latter from ringin 10. A selective signaling system coinpris ing a line-circuit. four signal-receiving" means connected with the said circuit, each signal-receiving means being grounded, and a calling apparatus" for selectively operating the said signal-receiving means over the said circuit, said calling apparatus including-a. couple ot'gencrators' conn'ectcd in series and grounded at a point between them, and eachsignal-receiving means coi'l'iprising a polarized electric bell. and an clcctro-magnet ln'idgcd in series with the coils of the bell and adapted when energized to prevent the latter from 1.inging. v

11. A selective signaling system comprising a linccircuit, tour signal-receiving means connected with the said circuit, each sigmil-rzceiving means being grounded, and a calling apparatus normally, disconnected from the said line-circuit, butadapted to be connected therewith for the purpose oi. lectively operating the saidsignal-receiving means, said calling apparatusincluding a plurality of generators connected in series and grounded at a point hetw'eenithem, together with a pluralityof ringing-keys controlling the flow of current from the generators to the line-circuit and corresponding in number to the said'signal-receiving means,

and each signal-receiving fr'neans comprising a polarized electric bell, and an ele'ctrom'oagnet bridged in series with the coils of thevbel'l andadapted when energizedto prevent the latter from ringin v 1' 12. A selective, s1gnaling system compris iug a metallic line-circuit, a plurality of signai-rcceiyingmeans bridged across the said circuit, eachbridge being grounded, and a calling apparatus normally disconnected from the said line-circuit, but adapted to be connected thereto for the purpose of selec tively operating said signal-receiving means,

said calling apparatus lncludi'ng a plurality of alternating current-generators connected in series and grounded at a point between them, together with a lurality of ringingl'teys whereof one'is a apted for including one-of said generators in' series with the ground and one side of the linecircuit, an other for connecting the other side ofthe line-cimuit in series with the ground and the other generator, another for connecting one of'the generators in a ground-circuit including both sides of the line-circuit in parallel, and the other for connecting bot-h generators in series in a complete metallic circuit including both sides of the line, and each sig-' nal-receiying means comprising a polarized electric bell, and an "electro magnet connected in series With the coils of the'bell and adapted when energized to preventtlf'e' 'lattcr from ringing.

13; A selective signaling system comprising a complete metallic subscribers. line, a

plurality of signal-receiving means bridged across the said circuit-,- each bridge being grounded and including a pair of condensers arranged at opposite sides ots-aid signalleceiving'nieans, and a calling alpparatus'norinally disconnected from the said line, but adapted to be connected thereto for the T9111: pose of selectively operating the said signalreceiving means over the said line,isaid-callingapparatus including a plliirality-of 'altcrnetting current igenerators, together" Wltll, switching devices adapted for variously connecting one or more of generators with either one or both sides of the line-circuit, and. whereby said generators may be connected up in as many difierent circuits as there are signal-receiving means, each sig- 'nail-receivinguneans being'responsive only when its allotted circuit is closed, and each sigmil-nmciring means comprising a polarized electric hell, and an clectro-magnet con-" nccted in series with the coils of the bell and adapted when energized to prevent the latte: from ringing.

4;. A selective signaling system C(JIIIPI'lS- ing" a line circuit, a plurality of signal-recei'ving u'icaus connected With the said circuit, and a calling apparatus for selectively operating said siginil-receiving means overthe said circuit, said calling apparatus in cluding a couple of synchronized alternating currnbgenerators, said generators being connected in series and grounded at a point between them, andeach signal-receiving means comprising an. electric hell or ringer, and an electro-magnet having two, calls connected in series with the coils of saidbcll, said magnet being adapted when energized to prevent the'hell from ringing.

15, A selective signaling system compris ring a linecircuit, aplurality of signal-recei ving means connected with the said circuit, each signal-receiving inn-ins, being V grounded, and a calling apparatus for selecconnected in series and grounded at a .point 106 between them. and each signal-receiving means comprising an electricbell or ringer, and an electro-magnethaving two coils con nected in series with the coils-ct said-bell, said magnet being adapted when energized to prevent thehell from ringing,themaeiating circuit of at least one signal-receiving means including the hell in series with a. winding of its associated. magnet.

'16. A selective signaling systenr'comprie in}; 'a line-circuit, a plurality of signahre ceiving means connected with the said .ci cuit, each signal-receiving means being; grounded, and a callingapparatus normally disconnected from the said line-circuit, but adapted to he connected-therewith for the purpose of selectively operating the said signal recoiying means, said calling appa' ratus including a plurality of generators connected in series and grounded at a ,point between them, togetherwith'alplurality of ringinglceys controlling the flow of current V v I from the gel'icrators to the liuc-circuit and corresponding in numher to the said signal-- re :eiyin'g means, and eachsignahreceiving -means conunis in an'el'ectric hell or ringer, and an electroan-agent having two coilscoiii'lccted in. HtdS with the coils of'said aloell said magnet la iug'mlapted when energizedto prevent thchell from ringing, the operat- 1 9 ing circuit 01 at least one signal-receiving means including the bell in' series with a winding of its associated magnet,

17. A selective signaling system comprising ametallic line-circuit, a plurality of signal-receiving means bridged across the said circuit, each bridge being e rounded, and a calling; apparatus normally disconnected from the said line-circuit, but adapted to be connected thereto for the purpose of selectively operating said signill-receiving means, said calling apparatus including a plurality of. alternating current-generators connected in seriesnnd grounded at a point between them, together with a plurality of ringingkeys whereof one adapted for including one of said generators in series with the ground and, one side of the line-circuit, an? other forconnecting the other side, of the line-circuit in series with the ground and the other generator, another for connecting one of the generators in a ground-circuit ineluding both sides of the line-circuit in parallel, and the other for connecting both generators in series in a complete metallic circuit including both sides of the line, and each signal-receiving meanscomprising an electric bell or ringer, and an electr'o-magnet having two coils connected in series-with the coils of said bell, said magnet being adapted when energized to prevent the bell from ringil'ig. i

18. A selective signaling system comprising a: complete metallic snbscribers line, a spring-jack in: which the said line terminates, a cord-circuit provided with a plug adapted for insertion in said ack, a plu-.

rality of alternating; eurrent-oenera-tors connected in series and groundtalat a point between them, a plurality of keys for variously connecting the gent-waters with either one or both sides oi. the cord-circuit, and a plurality of sigi'ial-receiving means bridged across the said line, each bridge being grounded, and. each signal-receiving means lmiiigr-adapted to be operated by 1ts allotted ""ltey and no other and each si rnal-reeeivine;

means comprising an electric bell orrinr-fer 411K181). electro-niagnet having two coils coirneeted'in. series. with the coils of said bell, said 'llttlQ-DP liming adapted when energized to prevent the bell from ringing.

'19; A 1selectivesignaling system comprising a conu'ilete metallic sub. 1 her-7s line, a plurality of signal-rm-eivinem ians bridged acrosssl'he said circuit, each bridge bring gfrounded and. inelndinn a pair of :ond-ens ers'arrani ed at opposite sides of said iial-receiiunn iueansg and a calling apparatus norn'ially disctmuertml iii-run the said line, but adapted to l'H onnected thereto (or the pin-posit! of'seha-tively operating: the-said signal-receiving uu'an over the said line said. calling apparatus Including a. plurality of alternating currcnt generators together with switching devices adapted for va'ri ously connecting one or more of said generators with either one or both sides of the l1ne-circuit, and'whereby said generators may be connectedup in as many differentcircuits-as there are signal-receiving means,

each signal-receiving means being responsive only when its allotted circuit is closed,

and each signal-receiving means comprising an electrlc hell or ringer, and an electro magnet having two coils connected in series ing a line-circuit, a-plurality of signal-receiving means connected with the said circuit, and calling apparatus for selectively operatingthe said signal-receiving means over the'said circuit, said calling apparatus including a couple of generators connected in series and grounded at'a point between them, and one of said signahreceiving means comprising an electric bell adapted to be ener gized when current passes through its two coils in series, an electro-lnagnet adapted when energized to prevent the bell from ringing, said ele'ctro-magnet being adapted to be energized, when current passes through its coil, together with aground connection extentli'iug from between the bell and electro-magnet, the operating circuit of at least one signal-receiving means including the bell in series With a winding of its associated magnet.

'21. A selective signaling system comprising a linecircuit, a plurality of signal-receiving means connected with the said circuit, each signal-receiving means being grounded, and a calling apparatus for selectively operating the said s nal-receiving nneans over the raid circuit, said calling ap v paratus including a couple of e'ei'ie'rators eonnectedin series and grounded at a pointbetween them, and one'of said signals-weirinn, means comprising an electric bell adapted to l)e*'energizetl when current passes through its two coils inseries, an electroniagnet adapted when energized to prevent the bell from ringing, said electro-magnet being adapted to be energized when current passes through-its coil, together with a ground connection extending from between the bell and elcctroanagnet, the operating circuit of at; least one signal-receiving means irmludinn' the hell. in series with a winding of its associated magnet. v

22. A selective signaling system comprising' a line-circuit, a ph-irality of signal-recei g'means connected with the said circuit, each signal deceiving means being grounded, and a'calling apparatus normally disconnected from the said line-circuit, but adapted. to be connectedtherewith tor the purpose of selectively operating the said ing means'comprising an electric bell aclapted '-to be energized when current passes through its two coils in series, an electromag' 'net'adapted when energizedto prevent the bell from ringing, said electro-magnet being adapted to be energized when current passes through its coil, together with a ground connection extending from between the bell and electro-magnet, the coil of theelectro mag net being connected in series with and at one side of the coils of the bell, the operating circuit of atleast one signal-receiving means including the bell in series with a winding of its associated magnet.

28. A selective signaling system comprising a line-circuit, a plurality of signal-receiving means connected with the said circuit, each signal-receiving means being grounded, and aicalling apparatus normally disconnected from the said line-circuit, but adapted to be connected therewith for the purpose of selectively operating the said signal-receiving means, said calling apparatus including a plurality of generators connected in series and grounded at a point between them, together with a plurality of ringing-keys controlling the flow of current from the generators to the line-circuit and corresponding in number to the said signalreceiving means, and one of said signal-receiving means comprising an electric bell adapted to be energized when current passes through its two coils in series, an electromagnet adapted when energized to prevent the bell from ringing, said electro-magnet being adapted to be energized when current passes through its coil, together with a ground connection extending frombetween the bell and electro-magnet, the coil of the electro-magnet being bridged in series with and at one side of the coils of the bell, the

operating circuit or" at least one signal-receiving means including the bell in series with a winding of its associated magnet.

29. A selective signaling system compr1s ing a line-circuit, a plurality of signal-receiving means connected with the said circuit, and a calling apparatus for selectively operating said signal-receiving means over the said circuit, said' calling apparatus 1neluding a couple of synchronized alternat ng current generators, said generators being connected in series and grounded at a pomt between them,-and one of said signal-receiving means comprising an electric bell adapted to be energized when current passes through its coils in series, an clectro-magnet provided with two coils and adapted when energized to prevent the bell from ringing, said electro magnet being adapted to be energiz'ed when current passes through one of its coils, but not when current passes through both of its coils inserics, and a connection extending to ground from a point between the coils otsaid electromagnet, the coils of 7 the elcctro-magnet being connected between and in series with the coils of the bell.

30. A selective signaling system comprising a line-circuit, a plurality of signal-receivlng means connected with the said circult, and calhng apparatus for selectively operating the said signal-receiving means -when.current passes through one of its coils,

but not when current passes through both ofits coils in series, and a connectlon extending to ground from apoint between the coils of said. electro-magnet, the coils of the electro-magnet being connected between and in series with the coils of the bell.

31. A selective signaling system comprisinga line-circuit, a plurality of signal-receiving means'connected with the said circuit, each signal-receiving means being grounded, and a calling apparatus for selectively operating the said signalreceiving means over the said circuit, said calling apparatus including a couple of generators connected in series and grounded at a point between them, and one of said signal-receiving means comprising an electric bell adapted to be energized when current passes through its coils in series, an' electro-magnet provided with two coils and adapted when energized to prevent the bell from ringing, said elect-ro-magnet being adaptedv to be energized when current passes through one of its coils, but not when current passes through both of its coils in series, and aconnection extending to ground from a point between the coils of said electro-magnet, the coils of the electro-magnet being connected between and in series with the coils of the bell.

32. A selective signaling system comprising a linocircuit, a plurality of signal-rcceiving means connected with the said circuit, each signal-receiving means being.

grounded, and a calling apparatus normally disconnected from the said line-circuit, but adapted to be connected therewith for the purpose of selectively operating the said signal-receiving means, said calling apparatus including a plurality of generators con nected in scriesand grounded at a point between them, together with a plurality of ringing-keys controlling the flow of current from the generators to the linecircuit and corresponding in number-to the said signalreccivjng means. and one of said signal-receiving means comprising an electric bell to be energized when current passes through its coils in series, together with a connection extending to ground from a print between the coils of said electroanagnet, the coils of said electro-magnet being connected between and in series with the coils of the bell.

- 42. A selective signaling system c'ol'n rising a line-circuit, a plurality of signa. -receiving means connected with the said circuit, each signalrreceiving .means being grounded, and a calling apparatus for Se lectively operating the said signal-receiving means over the said circuit, said ca-llingapparatus including a couple of generators connected in series and grounded at a point, betweenthem, and one of said s1gnal-fece1vgenerators 111 series in a complete metallic ing lneans comprising an electric bell adapted to be energi ed when current passes through its coils in parallel, but not when current passes through its coils in series, and an eleotro-inagnet provided with two coils and adapted when energized to prevent the bell from ringing, said electro magnet being adapted. to be energized whencurrent passes through its coils n series, together with a connection extending to. ground from a point between the 0011s ot said electro-rnag net, the coils of said electro-niagnet being connected between and in series with the 4-3. Aselec'tive signaling system comprising a line-circuit, a plurality of signaldi'e ceivingine'ans connected with the said circart, 3 each slgnal-rcccrvlng means being grounded, and a; calling apparatus normally disconnected from the saidflinemircuit, but adapted to be connected therewith for the purposeof selectively operating the said 'si 'nal-receivin means. said callin a Ja- L! t1 b ratus including aplurality of generators connected in series and grounded at a pointb'otwcien them, "together with aplurality of ringing-keys controlling the flow ot' currcnt from the generators to the line-circuit and corresponding in number to the said signalreceiving inc-ans, and one of said .sin'mil-re--v ceiving means'con'norising an electric bell adapted to be energized when current passes through its coils in parallel, but not when current passes through its coils in series,

and' an elcctrc'magnet provided with two ('oils and adapt id. when energized to prevent the bell from ringing, said electrounagnct being adapted to be energized when current passes through its coils in series, together with a connection extending to ground from a point between the coils of said. electromagnet, the coils of said electro-ma uet being connected between and in series with the coils of the bell.

44. A selective signaling T i \-Hl(lll cm'nprisiug a metallic liner-main, a plurality of S QI."

' and in series with the coils of the bell.

naljreceiving means bridg d across the said circuit, each bridge being grounded, and a calling apparatus normallv l.llHC 'J[ll'l( 'll(l ringing,

lectively operating said signal-receiving.

means, said calling apparatus including a plurality of alternating current-generators connected in series and grounded at a point between them, together with a plurality of ringing-keys whereof one is adapted for including one of said generators in serieswith the groundand one side of theline-circuit, 'another for connectingthe other side of the line-circuit in series with the ground and the other generator, another for connecting one of the generators in a ground-circuit including both sides of the line-circu-itdii parallel, and the other for connecting both circuit including both sides of the line,a11'd one of sald signal-receiving means compris ingan electric .bell adapted to,be energized when current passes through its coils in parallel, but not when current passes through its coils in series,.and an electrouna'gnet provided with two'coilsnnd adapted when energised to prevent the bell from ringing,- said electro-i-nagnet being adapted to be energizec'l when current passes through its coils in series, together with a connection extending to ground from a point between the COllS of sand electro-magnet, the coils of sald electro-niagnet bemg connected be-' tween and in series with the coils of the bell.

A selective signaling system compris ing a metallic line-circuit, a plurality of signal-receiving means bridged across the said line-circuit, each bridge being grounded. .and including a pair of condensers arranged at. opposite sides of the signalreceiving Jneans, and a calling apparatus for selectively operating the said signaLrecciving means over the said line'ci-rcuit, said calling apparatus including a. plurality of alternat ing cui.-r-cnt-.-gei1craters connected in'ser'ies, and each connected with ground, together with a plurality of selective, ringingakeys corresponding innumbcr toy/the signal-re ceiving means, and adapted for connecting up the generators in as manydifi'erent circuits as there are signal-receiving means,

and one of said signal-receiving ineans co'm prising an electric bell adapted to be energized when current passes through its coils in parallel, but not when current passes through its; coils in series, and an electromagnet providiwl with two coils and ada t-ed when energized to preventthe bell from d ('llilHFl'nilgnGb being adapted to be energized when current. passes through ils coils in series, together with a connection extending to ground from a point between the coils of said el'ectro-nmgnet, the coils of sa id electro-magnet bein'g connected between 4-6, A selective signaling system cornpris ing a complete metallic subscrl-bers lmeJa sprin -j ack in which the said line terminates, a cor -circuit provided with a plug adapted for insertion in said jack, a plurality of alternating current-generators connected in series and grounded at a point between them, a plurality of keys for variously connectin the generators with either one. or both sides of the cord-circuit, and a plurality of signal-receiving means bridged across the said'line, each bridge being grounded, and

each signal-receiving means being adapted to be operated by its allotted key and no other, and one of said signal-receiving means comprising an electric bell adapted to be energized when current passesthrough its coils in parallel, but not when current passes through its coils in series, and an electromagnet provided with two coils and ada ted when energized to prevent the bell rom ringing, said electro-magnet being adapted to be energized when current passes through in series, and

when current passes through 'SGIIGS, together with'a connection extending its coils in series, together with a connection extending ..to ground from a point" between the coils of said electro-magnet, the coils of said electro-magnet being connected between and in series with the coils of the bell.

47. A selective signaling system comprising .a complete metallic subscribers line, a plurality of signal-receiving means bridged across the said circuit, each bridge being grounded and including a pair of condensers arranged at opposite sides of said signal-receiving means, and a calling apparawhen its allotted circuit is closed, and onepfsaid signal-receivin means comprising an electric bell adapt-ec l current passes through its coils in parallel, but not when current pa sses .throughits coils an electro-magnet provided with two coils'and adapted when energized to prevent the bell from ringing, said electro-magne't being adapted to be energized its; coils in to ground from a point between the coils of said electro-magnet, the coils'of said electro magnetbeing connectedbet'ween and in series with the coils or the 'be1l-.

48. "A "selectivesignaling system compris inga-plurality of signalieceiving' means, to-

vgetjier with means' for selectively operating ringing,

to prevent the bell from ringing,

to be energized whenw gethcriwith a from between the burned 'electro-Inagnet,

the said signal-receiving means, and each signal-receiving means comprising a polarized ringer, and a magnet adapted when energized to prevent the bell from ringing, the

operating circuit of at least one signal-receiving' means including the bell in series with a winding ofits associated magnet.

' 49. A selective signaling system comprising, a plurality of signal-receiving means,

togetherwith means for selectively operating the said signal-receiving 1neans, and each signal-receiving means comprising a polarized electric'bell, and an electro-magnetcon nected in series with the coilsof the 'bell and adapted when energized to prevent the lat ter from ringing, the operating circuit of at least one signal-receiving means including he bell in series with a winding of its associated magnet.

50. A selective signaling system compris-- ing a plurality ol signal-receiving means, together with means for selectively operating the said signal-receiving means, andeacli slgnal-receiving means comprising an electric hell or ringer, and an electro-magnet having two coils connected in series with the coils of said bell, said magnet being adapted when energized to prevent the bell from signal-receiving means including the bell in series with "a. winding of its associated magnet. v I

51. A selective signaling system comp'ris the operating circuit of at least'one ing-a plurality-of signal-receiving means, to-

getherwith means for selectively operating the said signal-receiving means, and one of said signal-receiving means comprising an electric bell adapted to be energized when current passes through its two coils in series, an electro-magnet adapted when energized said electro-magn'et being adapted to be energized when current passes through its coil, to ground connection extendingfrom between the bell and electro-magnet,

gether with a the operating circuit of at least one signalreceiving means including the bell in series with a winding of its associated magnet.

j 52. A selective signaling system comprising a plurality of signal-receiving means, together with means for selectively operating the said. signal-receiving means, and one of said signal-receiving means comprising an electric bell adapted to be energized when current passes through its two coils in series, an clectro-inagnet adapted when energized to prevent the bell from ringing. said electro-inagi'ict being ndapted to be energized when current passes through its coil, to-

ground connection extending the coil the electrQ ma'gnet'heingconnected in series with and atlonesi e of the of the bell. the operatingici rei-iitt'of -a.t.l ist coils one signal-receiving means including the bell in series with a winding of its associated magnet A selective signaling system comprising a plur ality Jo. E signal recei ving means, together with means for selectively operating the said signal-receiving means, and one of said signa'l'receiving means comprising an electric bell adapted to be energized when current passes through. its coils in series, an eleot'ro-magnet provided with two coils and adapted when energized to prevent the bell from ringihg, Jsaid electro magnet being adapted to be energized when current passes through one of its coils, but not when current passes through both of its coils in series, and a connection extending to ground from a point between the coils of said electromagnet, the coils or the electromagnet being connected between and in series with the coils of the bell."

54. A selective signaling system comprising a plurality of signal-receiving means, to,- gether with means for selectively operating the said signaLreeeiving means, and one of .said signal-i'eceit'mg means con'lprising an eleetricbell. adapted to be energized when current passes through its coils in parallel, but not when current passes through its coils in series, and an electro magnet provided with two coils and adapted when energized to preventthe bell from ringing, said electro-inagnet being adapted to be energized when current passes through its coils in series, together with a connection extending to ground from a. point between the coils of said electrounagnet, the operating circuit ofht least one signal-receiving means including the bell in series with a winding of its associated magnet.

-55. A selective signaling system comprising a plurality of signalreceiving means, to-

gether with means for selectively operating the said signal-receiving means, and one of said signal-receiving means comprising an electric bell adapted to be energized when current passes through its coils in parallel, butnot when current passes through its coils in series, and an electro-Inagnet provided with twocoils and-adapted when energized to prevent the bell from ringing, said electrormagnet being adapted to be energizedwhen current passes through its coils in series, together with a connection extending to ground from a point between the coils of said 'clect-ro-inagnet, the coils of said electromagnet being" connected between and in series with the coils of the bell. 56. A selective sigl'ialing systeni, comprising a lincarircuit, a plurality of signal-receiving means each bridged across the said circuit, together with means for selectively operating the said signal-receiving means,'- each signal-receiving means comprising an electric bell and an electro-magnet connect ed in series, each electro-magnet having two coils and being adapted when energized to prevent its allotted bell from ringing, 'two of said bridges being grounded from a point between the electric bell and the electro-1nagnet,'and two of said bridges being grounded froina point, between the coils of the electro-magnet.

57. it selective signaling system comprising a line-circuit, a plurality of signal-receiving means connected in parallel across the said circuit, means including a plurality selectively operating said-signal-receiving means, each signal-receiving means com prising an electric bell andan electro-magnet connected in series across the line-circuit, each electrdmagnet having two coils and being adapted when energized to prevent its allotted bell from ringing, a pluconnected to groundfrom a point between the electric bell and the elecdao-magnet, and a plurality of said. signal-receiving means being connected to ground from apoint be tween the coils of'theelectro-magnet.

58. A selectivesignaling system comprising a line-circuit,'an'electric bell and an eleetro-magnet bridged in series across the point between them, said electro-magnet being arranged at one side of the bell, another electric: bell and electro-magnet similarly bridged across the line-circuit and connect ed to ground from a point between. them, but the 'electro-magnet in this case bein arranged at the other side of the be another electric bell and electro-n1agnet bridged across the line-circuit and connected to ground from a point between the coils of the electro-magnet, the electro-magnetin this case having two coils and being connected between the coils of magnet connected in series across the linecircuit and grounded at a pointbetween the coils of the electron\ap'uet, the chemo-mag net in this case having two differential coils bell, a plurality of alternating carrentgencraters connected in series and grounded at a point between them, and switching appaators in as many different circuits as there are electric bells, whereby any electric bell may be rung to the exclusion of all others on the same line. i

combination of a telephone line, a plurality of substations on said line, aringer at each sllbSitltiOIl, a ringing circuit for each rii'lger, an QlQCtL'OJHfigIIQl? for each ringer, and means for supplying alternating ringrality of said signal-receiving means being line-circuit and. connected to ground from a the bell, another electric bell and electrosand being connected between the coils of the ratus for variously connecting the genera oftgrounded sources of current supply for 59; In a telephone exchange system, the.

, magnet provided with means for prevent- .'tively operate said ringers, each electro- 4 of substations on said line, a ringer 'ateach .ringer, an electrdmagnetfor each ringer, and means for supplying alternating ringing currents through said circuits to selec-,

ing currents through said circuits to selectively operate said ringers, each electroi-ng all except the proper current from operating its allotted ringer, one of said electromagnets provided, with two windings included in series in the ringing circuit of its ringer.

60. In a telephone exchange system, the combination of a telephone line a plurality of substations on said line, aringer at each substation, a ringing circuit for each ringer, an electro-magnet for each ringer, and means for supplying alternating ringing currents through said circuits to selecmagnet' provided with means for preventing all except the proper current from oper-- at-ing'its allotted ringer, one of said electromagnets provided with two. windings included in series in the ringing circuit of its ringer, said windings being connected to ground at a point between them, said current supply means being also grounded.

61. In-a telephone exchange system, the combination of a telephone line, a plurality substation, a ringing circuiti'or each tively operate said ringers, each electromagnet provided -with means for preventingall except theproper current from operating its" allotted ringer, one of said electro-magnets provided with two windings included in series 1n the ringing clrcult of its ringer, the SH10l windings being adapted to oppose-each otherwhen the ringer allot-' ted thereto is operated.

62. In a telephone exchange system, the combination of a telephone line, a plurality of substations on said line, a ringer at each substation, a ringing circuit for each ringer,

an electro-magnetfor each ringer, and

means for supplying alternating ringing (33.111 a telephone system, a party-line,

a couple of synchronized genera-tors, a ringing circuit including the two generators in series iviththe two sides of the line, and means for bridging the said generators on the 'line. p

Signed by me at Chicago, Cook county, Illinois, this 27th day of-July, 1905.

.JOHN ERICKSON. Witnesses:

.11. C. Grrronn,

IV. LEE CAMPBELL. 

